Childhood exposure to air pollution directly linked to adult bronchitis

New research carried out by a team at the University of Southern California’s Keck School of Medicine  has found evidence of a link between long-term exposure to air pollution in childhood with the development of bronchitis symptoms as an adult.

It has long been established that lung problems during childhood can be associated with exposure to air pollution, which consequently leads to lung problems in adulthood. This study is one of only a few to show a direct link between childhood air pollution exposure and adult lung health, opening, they say, ‘the possibility of yet-to-be-understood factors explaining the path from early air pollution exposure to respiratory maladies many years later.’

The team used 1,308 participants on the decades-long USC Children’s Health Study, which follows a cohort of Californians from school-age into adulthood.

The participants, who had an average age of 32 at their assessment, were asked about recent bouts of bronchitis symptoms — having either bronchitis, chronic cough or congestion, with a quarter of them confirming that they had experienced such symptoms within the previous year.

Average pollutant exposure over childhood was based on month-by-month estimates based on air quality measurements taken ‘ by the EPA and through the Children’s Health Study itself. Applying this information with the participants’ family home address, it was revealed that the presence of bronchitis symptoms was associated with exposure to PM2.5 and NO2 between birth and age 17.

The significance of the study was that it ruled out factors such as prenatal exposure to NO2, air pollution exposure as adults and the impact of socioeconomic status as potential causes of bronchitis symptoms in adults.

Erika Garcia, PhD, MPH, assistant professor of population and public health sciences at the Keck School of Medicine explains the relevance of this: ‘We would expect that these observable impacts on childhood respiratory health would explain the relationship between childhood air pollution exposure and adult respiratory health. Our results suggest that childhood air pollution exposure has more subtle effects on our respiratory system that still impact us in adulthood.’

It was also found that childhood exposure to NO2 and PM2.5 exacerbated bronchitis symptoms among adults who had been diagnosed with asthma as kids.

Garcia said: ‘There may be a subpopulation that is more sensitive to the effects of air pollution. We may want to be especially careful to protect them from exposure, so we can improve their outcomes later in life. Reducing air pollution would have benefits not only for current asthma in children but also for their respiratory health as they grow into adulthood.’

The team are now working to discover how air pollution exposure at different ages during childhood influences breathing issues as an adult.